Mike is confused -- about your right to a "second opinion" before the minus lens is used

Discussion in 'Optometry Archives' started by Otis Brown, Aug 27, 2004.

  1. Otis Brown

    Otis Brown Guest

    Dear Friends,


    Subject: Mike's majority opinion (box-camera theory) versus the
    second-opinion concerning the eye's ability to control
    its refractive state to its accommodation signal.


    Otis> I object to Mike's statement, "except for you", since I am
    well-aware that other ODs and MDs who actually examine
    objective-factual data have reached the conclusion that the
    eye is dynamic in its fundamental behavior characteristic.


    Re:> It is not obvious (except to you) that the eye grows longer
    and shorter depending on what lens you place in front of it.
    - Mike Tyner


    Otis> It has become obvious to scientists and ophthalmologists
    that in fact the natural eye does change its REFRACTIVE
    STATUS as the accommodation SIGNAL is changed. I know you
    like to attack me -- because I state objective, scientific
    factual truth concerning the natural eye's behavior. Here
    is Dr. David Guyton (John Hopkins Hospital) statment about
    Mike's belief -- that the eye DOES NOT grows longer and
    shorter depending on what lens you place in front of it. I
    regret the fact that you are technically out-of-date
    concerning this issue, and you think that the majority opinion is the ONLY
    opinion. Dr. Guyton (Professor of Ophthalmology - JHU)
    makes his statement about the ability of the eye to
    adjust its refractive state (as a natural process) as enviroment is
    changed. To make certain I do not miss-quote him -- here is
    his statment:

    _______________________________


    The Physician's Perspective -- David L. Guyton, MD


    According to old-wives' tales, wearing glasses makes the eyes
    worse. Generations of ophthalmologists and optometrists have told
    their patients just the opposite, that the eye's development is
    predetermined by genetics and cannot be affected by glasses. A
    growing body of animal and human research, however, suggests that
    the old wives were right after all.

    The ability of young rhesus monkeys' eyes to gradually change
    shape in response to what they see comes as no surprise to vision
    scientists. Over the past two decades, their studies have
    demonstrated that the eyes of young birds, tree shrews, guinea
    pigs, and marmosets react to unfocused images by altering their
    growth to correct the problem.

    It is highly likely that the eyes of infants and young
    children also adapt to what they see. This adaptation occurs by a
    relative change in eye length that works something like this: As
    the front of the eye grows and becomes less curved, images focus
    deeper and deeper within the eye. If the lengthwise growth
    perfectly matches the change in the eye's other dimensions, then
    images continue to focus on the retina. If there is a mismatch
    and the focus is off by even the thickness of this paper, then
    vision will be blurred. Remarkably, the eye apparently senses
    where images focus and compensates when needed. If light focuses
    in front of the retina, the eye will stop lengthening until the
    images catch up. If the focus is behind the retina, the eye grows
    in length at an accelerated rate until the retina is "pushed back"
    to the correct spot relative to the eye's other dimensions.

    Thanks to this feedback mechanism, the eyes generally
    maintain clearly focused images throughout early life despite
    dramatic changes in size.

    In addition to eye size and shape, the distance between the
    eye and the objects it is viewing also determines where images
    focus. Near objects come to focus behind the retina, but the lens
    changes shape and pulls the images forward until they are clear
    enough to recognize. However, they often remain slightly behind
    the retina. This slight mismatch may be the mechanism by which
    prolonged close work such as reading can signal the eye to grow
    longer. If such a signal occurs frequently and strongly enough in
    early life, the human eye may gradually lengthen and become
    permanently focused for near objects. This produces
    nearsightedness.

    Most of the adaptive changes in eye length occur during
    infancy and youth, while the eye is still growing in its socket.
    When the front of the eye stops growing, around age nine or ten,
    any further adaptive change can occur only in the myopic direction
    -Ä the eye can grow longer, but not shhorter. Activities such as
    prolonged reading at close distances may cause the eyes to
    continue lengthening well into one's 20s.

    If this cycle of incomplete focus and eye lengthening is the
    primary cause of myopia, how can we intervene in this process?


    Some practitioners believe that limiting the amount of
    close-up reading or television watching a child or young adult
    does each day may prevent myopia. These days that is a difficult
    task. So I advise parents to encourage children to hold objects
    and reading materials as far away from their faces as comfortable,
    and to sit at least three feet away from the television screen.
    (Those who insist on holding books close to their eyes, or sitting
    a foot from the television or computer, may already have developed
    significant myopia or some other problem that warrants a
    professional eye examination.)

    For my young patients with simple myopia, I suggest they
    leave their distance glasses off while reading, something I have
    always done myself. A child who cannot see the board at school,
    for example, should wear glasses to see the board, but remove them
    when reading a book or writing.

    Prolonged reading without glasses shouldn't stimulate the eye
    to lengthen any farther than what is needed to comfortably focus
    the eye at rest at the customary reading distance. By comparison,
    when one reads through glasses or contact lenses designed to bring
    the distant world into sharp focus, the page is focused behind the
    retina. This may prompt another round of eye lengthening with
    worsening of the myopia.


    _____________________________



    From: "Otis Brown" <>


    Subject: Mike and his protective story. What is pure science?
    What is the fundmental fact about the dynamic behavior of
    the natural eye? Does the refractive state of the
    natural eye "move negative" when you place a minus lens
    on the natural eye -- or does it not?


    Oakham's Razor: The philosophic rule that entities should not be
    multiplied unnecessarily.


    In other words, you should not invent additional explanations
    about the experimental data that are more complex, and more
    difficult, when a simpler explanation has already been provided.

    If each experiment requires its own theory and explanation,
    then we will have chaos. If we are not looking for fundamental
    scientific truth, then why are we doing these experiments?


    ___________________


    Re:> It is not obvious (except to you) that the eye grows longer
    and shorter depending on what lens you place in front of it.
    -MT

    Otis> Again, Mike totally ignores the published scientific
    literature from Dr. Dave Guyton. (i.e., eyes lengthen and
    shorten as the visual environment is changed.) At the very
    least Mike should state his belief as the "Majority"
    opinion, and acknowledge that a highly qualified
    ophthalmolgists holds the contrary, or "Second" opinion as I
    do. Further, I am willing to restrict my statement to only
    what a scientist actually MEASURES -- i.e., a refractive
    state.

    Otis> I have said nothing at all about "length". What I stated
    was a matter of a DIRECT MEASUREMENT. A "length" is an
    extrapolation of your box-camera theory -- which is a matter
    of a convenient shop-practice theory.

    Mike> No, "length" is something measured with ultrasonography.
    You're familiar with ultrasound? A-scan, B-scan, all that
    stuff? You know it shows myopes change axial length, right?

    Otis> If we would restrict our words to ONLY direct measurement
    you would establish that a population of natural eye "moves
    down" it terms of refractive status, and a function of a
    step-change in the average visual-environment.

    Mike> 2/3 of the US population doesn't "move down."

    Otis> Instead of using basic, clear language

    Otis> Again, Mike is both restrictive and blind. He fails to
    mention that 92 percent of people in highly intensive "close
    work" professions, like medicine develop nearsightedness.
    (Ref: Doctors on Taiwan -- published report.)

    Mike> Basic and clear like "move down"?

    Otis> ... you must "spin" very basic analysis and make eyes that
    have 20/20, and normal refractive states appear defective
    (error, hyperopia, ametropia, and the like)

    Mike> So let's stop calling numbers to the left of zero
    "negative". "Negative" implies "defective" so we shouldn't
    use that term.

    Otis> ... Because of the ASSUMPTIONS you have made -- that have
    never been proven -- on a scientific level.

    Mike> I ASSUME that optometrists stopped prescribing plus for a
    reason.

    Otis> Clearly the meaning of words is critical in understanding
    that the natural eye is not a frozen box-camera.

    Mike> So who considers the eye a "frozen box camera"? We measure
    its changes over time, every day. We measure, you imagine.
    Which of us has better data?

    Otis> You can "freeze" the eye to do an "optical analysis", and I
    understand that analysis, and the reasons for such an
    "idealization".

    Mike> I don't freeze anything, nor do I call refraction "optical
    analysis".

    Otis> But then you completely forget what you have done.

    Mike> No, I write it down.

    Otis> You dissect and eye and find all the parts.

    Mike> I've never had to dissect anything to measure changes in
    refraction from year to year.

    Otis> What you have is a DESCRIPTIVE theory. If you wish and
    accurate PREDICTIVE theory, then you must consider the
    natural eye to be dynamic -- and test ONLY the natural eye
    for its dynamic properties.

    Mike> Before you can predict change, you must measure change. You
    haven't done that.

    Otis> That is what I mean by "alter our point-of-view" which you
    obviously do not understand.

    Mike> Obviously it's _MY_ understanding that's lacking here.

    Otis> That is _YOUR_ understanding as the "majority" opinion,
    versus Dr. Dave Guyton's understanding about the behavior
    of the fundamental and natural eye.

    Otis> Indeed you do _FAIL_ to understand the fact that the natural
    eye is dynamic with respect to shifts or "deltas" in its
    average visual environment. This is a completely _EXPECTED_
    behavior characteristic of the natural eye.


    Best,

    Otis

    -MT


    Date: Sunday, August 22, 2004 1:12 PM


    Dear Friends,


    I will post this to you from Mike (OD) for what it is worth.
    In science a DIRECT measurement is what YOU measure. An
    extrapolated statement is an assumption.

    Mike has made it a habit of insisting that his box-camera
    (never-proven theory) some-how PROVES that the refractive status
    of the dynamic eye does not CHANGE when you place a minus lens on
    it.

    I am certain of my statement here and I will place a $10,000
    wager on the outcome of this type of experiment -- against equal
    money that says that it will not. While this is the nature of
    SCIENTIFIC (not medical) proof, it does have consequences for all
    of us.

    I am certain that Mike will figure out some way to weasel out
    of facing direct scientific facts of this nature, and avoid
    confronting the reality that the natural eye has always been
    dynamic in the above sense.

    But it must be you alone who decides this issue.

    The reference is from, "How to Avoid Nearsightedness", Chaper
    10, which I posted on sci.med.vision.

    Best,

    Otis
     
    Otis Brown, Aug 27, 2004
    #1
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